Regardless of whether the president wins reelection, the Obama era will be over before long. Democrats will have to find a new leader on whom to pin their hopes. But who?

I went to a conference of liberal activists this week hoping to find out who the party's activist base sees as its up-and-coming stars. But the exercise turned out to be revealing largely for how unprepared people were to answer the question. Nearly every answer I got began with a blank stare or incredulous laugh, followed by some fumbling around, followed by "Elizabeth Warren."

Confirming the impression I'd gleaned from my conversations with activists and organizers, Warren ran away with the 2016 straw poll conducted at the Take Back the American Dream conference in Washington, winning 32 percent of the vote to Secretary of State Hillary Clinton's 27 percent. Ohio Sen. Sherrod Brown, who spoke at the conference and whose brand of gravelly-voiced populism is a perpetual hit with this crowd, was third with 16 percent; the other names on the ballot, all polling in single digits, were New York Gov. Andrew Cuomo, Vice President Joe Biden, and Virginia Sen. Mark Warner.

It tells you something about Warren's status as a rock star of the left that before the Massachusetts Senate candidate has even won her first election she's being pumped as a future presidential candidate. But it tells you even more about the status of the Democratic farm team. There are precious few tabbed for political stardom in the Democratic ranks the way Obama was starting in 2004 or the way Marco Rubio is adored on the right today.

"Whew, man, that's a tough one," said Jeanette Baust, a 55-year-old educator and activist from Denver who was attending the progressive conference along with her partner, Evelyn Hanssen. "I guess I'd have to say Elizabeth Warren if she can get elected." What about Colorado's Democratic senators, Michael Bennet* and Mark Udall, and governor, John Hickenlooper? The women didn't think they had national potential.

The bench of up-and-coming talent in the Republican Party is an instructive contrast. A recent straw-poll ballot for vice presidential choices at the Conservative Political Action Conference in Chicago featured 22 names, from retreads like Newt Gingrich to fresh faces like Rubio to newly minted political stars like Wisconsin Gov. Scott Walker. Nine major Republican candidates participated in this year's presidential primary, and while it was seen as a weak field overall, Republicans dismayed by the spectacle of Michele Bachmann and Herman Cain as momentary front-runners comforted themselves by contemplating the party's many future stars in the Senate, House, and governorships. Many of those rising stars, like New Jersey's Chris Christie, Louisiana's Bobby Jindal and Virginia's Bob McDonnell, have already begun building relationships with their party's national base by appearing at party events outside their home states or on the busy circuit of conservative activist conferences.

Democratic insiders, on the other hand, would be hard pressed to come up with 10 names for 2016, much less 20. The very short list of newcomers tabbed for big things seems to consist of Cuomo, Maryland Gov. Martin O'Malley, and Montana Gov. Brian Schweitzer, but they are far from household names even among Democratic die-hards; you are just as likely to hear speculation about another candidacy for Clinton or Biden -- who would be 69 and 74, respectively, at the time of their 2017 inaugurations.

Many Democrats acknowledge the looming talent gap and give the GOP credit for its candidate recruitment and training in recent years. They are trying to match that effort down the line: Numerous sessions at the Take Back conference focused on candidate development at the minor-league level, informed in part by state-level controversies that have recently made national news, from the recent Wisconsin recall to numerous states' abortion-ultrasound bills. Even as they had trouble coming up with names for 2016, many at the conference were eager to tout up-and-coming candidates currently incubating at the state legislative or congressional-contender level.

"There's a growing investment in the farm team by a lot of national groups that are thinking about what's happening in the states a lot more," said Adam Green, co-founder of the Progressive Change Campaign Committee. (His pick for 2016: Elizabeth Warren -- who, he notes, would by that time have the same amount of Senate experience as Obama had in 2008.) It's a matter of quality as well as quantity, he said. "We need to train people to fight so that they are actually fighters when they get to Congress, not just votes."

These efforts are gaining steam, said Gloria Totten, president of Progressive Majority, whose mission is to elect progressive candidates to statehouse and congressional seats. The group has trained 234 candidates who are running this cycle. But as for who might succeed Obama, she drew a blank: "Yikes," she said.

Many on the left defend the lack of readily apparent future presidential candidates by saying they're building a movement, not a cult of personality. "I see the progressive movement as the rising star in the Democratic Party," Rep. Keith Ellison of Minnesota said in an interview. "I'm very reluctant to identify charismatic individuals. I know they excite us and we want to know about them, but the truth is, there will be excellent vessels to carry the message, but it's the message [that matters], you know what I'm saying?"

Ellison did acknowledge that Republicans have done a better job bringing fresh blood into their ranks, especially in Congress. "Here's the reality," he said. "Democrats were out of power for a long time, so once they finally get in the majority, they don't want to move. Quite frankly, sometimes you have leaders who have been around quite a long time." He pointed to the dynamic young trio of Republican House leaders -- Majority Leader Eric Cantor, Majority Whip Kevin McCarthy and Budget Committee Chairman Paul Ryan, all under 50 -- as counter-examples: "It might not be a bad idea to look at what the Republicans are doing."

Democrats, on the other hand, are still led in the House by 72-year-old Nancy Pelosi. "Nancy Pelosi is one of the most vigorous people I've ever met in my life -- I'm not making an age argument," Ellison said. "There are occasions, though, when we need to understand for the continued viability of our party, our values, it's all right to let someone else come in."

I pressed Ellison for names for 2016, and he thought for a moment. "If we can get Elizabeth Warren through in Massachusetts, she could end up being a presidential candidate," he finally said. "She's super."